Commit 1746fd44 authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

tracepoints: Remove unnecessary "data_args" macro parameter 

While working on a clean up that would restructure the difference between
architectures that have static calls vs those that do not, I was stumbling
over the "data_args" parameter that includes "__data" in the arguments. The
issue was that one version didn't even need it, while the other one did.
Instead of injecting a "__data = NULL;" into the macro for the unneeded
version, just remove it completely.

The original idea behind data_args is that there may be a case of a
tracepoint with no arguments. But this is considered bad practice, and all
tracepoints should pass something to that location (that's what tracepoints
were created for).

Link: https://lkml.kernel.org/r/20210208201050.768074128@goodmis.org



Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 2d396cb3

include/linux/tracepoint.h

+11 −20
Original line number Diff line number Diff line
@@ -160,13 +160,8 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
/*

 * it_func[0] is never NULL because there is at least one element in the array

 * when the array itself is non NULL.

 *

 * Note, the proto and args passed in includes "__data" as the first parameter.

 * The reason for this is to handle the "void" prototype. If a tracepoint

 * has a "void" prototype, then it is invalid to declare a function

 * as "(void *, void)".

 */

#define __DO_TRACE(name, proto, args, cond, rcuidle)			\

#define __DO_TRACE(name, args, cond, rcuidle)				\

	do {								\

		struct tracepoint_func *it_func_ptr;			\

		int __maybe_unused __idx = 0;				\
@@ -194,7 +189,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
			rcu_dereference_raw((&__tracepoint_##name)->funcs); \

		if (it_func_ptr) {					\

			__data = (it_func_ptr)->data;			\

			__DO_TRACE_CALL(name)(args);			\

			__DO_TRACE_CALL(name)(__data, args);		\

		}							\

									\

		if (rcuidle) {						\
@@ -206,17 +201,16 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
	} while (0)



#ifndef MODULE

#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) \

#define __DECLARE_TRACE_RCU(name, proto, args, cond)			\

	static inline void trace_##name##_rcuidle(proto)		\

	{								\

		if (static_key_false(&__tracepoint_##name.key))		\

			__DO_TRACE(name,				\

				TP_PROTO(data_proto),			\

				TP_ARGS(data_args),			\

				TP_ARGS(args),				\

				TP_CONDITION(cond), 1);			\

	}

#else

#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)

#define __DECLARE_TRACE_RCU(name, proto, args, cond)

#endif



/*
@@ -231,7 +225,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
 * even when this tracepoint is off. This code has no purpose other than

 * poking RCU a bit.

 */

#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \

#define __DECLARE_TRACE(name, proto, args, cond, data_proto)		\

	extern int __traceiter_##name(data_proto);			\

	DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name);	\

	extern struct tracepoint __tracepoint_##name;			\
@@ -239,8 +233,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
	{								\

		if (static_key_false(&__tracepoint_##name.key))		\

			__DO_TRACE(name,				\

				TP_PROTO(data_proto),			\

				TP_ARGS(data_args),			\

				TP_ARGS(args),				\

				TP_CONDITION(cond), 0);			\

		if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) {		\

			rcu_read_lock_sched_notrace();			\
@@ -249,7 +242,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
		}							\

	}								\

	__DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args),		\

		PARAMS(cond), PARAMS(data_proto), PARAMS(data_args))	\

			    PARAMS(cond))				\

	static inline int						\

	register_trace_##name(void (*probe)(data_proto), void *data)	\

	{								\
@@ -332,7 +325,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 




#else /* !TRACEPOINTS_ENABLED */

#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \

#define __DECLARE_TRACE(name, proto, args, cond, data_proto)		\

	static inline void trace_##name(proto)				\

	{ }								\

	static inline void trace_##name##_rcuidle(proto)		\
@@ -412,14 +405,12 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
#define DECLARE_TRACE(name, proto, args)				\

	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),		\

			cpu_online(raw_smp_processor_id()),		\

			PARAMS(void *__data, proto),			\

			PARAMS(__data, args))

			PARAMS(void *__data, proto))



#define DECLARE_TRACE_CONDITION(name, proto, args, cond)		\

	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),		\

			cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \

			PARAMS(void *__data, proto),			\

			PARAMS(__data, args))

			PARAMS(void *__data, proto))



#define TRACE_EVENT_FLAGS(event, flag)